Term | Quality Index | |
Industry Grade | Food Grade | |
Purity ( As Na2SO3) | 96.0% min | 98.0% min |
Sodium sulphate ( SO4) | 2.5% max | 1.5% max |
Chlorides ( As NaCL) | 0.5% max | 0.1% max |
Arsenic ( As ) | - | 0.0002% max |
Heavy metals ( As Pb ) | - | 0.0005% max |
Iron (Fe) | 0.005% max | 0.002% max |
Water insolubles | 0.05% max | 0.02% max |